Sandblasting apparatus



Aug. 31, 1943. E. H. LINDENMEYER 2,328,350

' SAND BLASTING APPARATUS Filed April 22, 1941 2 Sheets-Sheet l Gttorncg Aug. 3l, 1943. 2,328,350

E. H. LINDENMEYER SAND BLASTING APPARATUS Filed April 22, 1941 2 Sheets-Sheet 2 Gttorneg Patented Aug. 31, 1943 SANDBLASTING APPARATUS "Elmer H. Lindenmeyer, Ottawa, lll., assignor to Libbey-Owens-Ford Glass Company, Toledo, Ohio, a corporation of Ohio Application April 22, 1941, Serial No. 389,788

6 Claims.

The present invention relates broadly to sand blasting apparatus and more particularly to apparatus for sand blasting glass.

Although the invention is obviously not limited to any specific use, it has been prmarly designed for and is of utility in applying a trade-mark or the like to sheets or plates of composite safety glass. It is customary for manufacturers of safety glass, including the company to which this application is assigned, to mark their glass to indicate its origin, the type of glass, such as Safety plate or Safety sheet, and/or its date of manufacture. This marking is ordinarily applied by projecting a sand blast upon the glass through a suitably cut stencil.

Sand blasting apparatus heretofore provided for this purpose has not proven entirely satisfactory due principally to the fact' that the marking has not been of a uniform character. That is to say, the opposite ends of th'e wording or lettering stenciled upon the glass is not as clearly outlined or dened as is the central portion thereof. This condition is ofcourse highly objectionable and particularly so when relatively small wording or lettering is used such as is usually the casein marking safety glass.

An important object of this invention is the provision of sand blasting apparatus of novel and improved construction which will effect a uniform cutting action upon the glass so that all portions of the wording, lettering or other marking will be evenly and clearly outlined.

Another important object of the invention is the provision of sand blasting apparatus of the above character embodying an improved nozzle construction for delivering the mixture of sand, emery or other abrasive used and air and for effecting a more uniform mixing and application thereof to the glass.

Another important object of the invention is the provision of sand blasting apparatus of the above character embodying means under the control of the operator for clamping the glass firmly in place thereupon and for substantially simultaneously causing the sand blast to be forcibly ejected against the glass.

A further important object of the invention is to simplify and improve generally the structure and operation of sand blasting apparatus of the above character to provide an apparatus which can be rapidly and easily operated to obtain constant uniform results.

Other objects and advantages of the invention will become more apparent during the course of the following description, when taken in connection with the accompanying drawings.

In the drawings, wherein like numerals are employed to designate like parts throughout the same:

Fig. 1 is a side elevation ci sand blasting apparatus constructed in accordance with this invention;

Fig. 2 is a plan view of a portion ofthe apparatus;

Fig. 3 is a vertical sectional view through the apparatus taken substantially on line 3-3 of Fig. 1; and

Fig. 4 is a detail View of the means for controlling the flow of abrasive from the nozzle.

Referring now to the drawings, the apparatus comprises a rectangular supporting frame 5 composed of vertical legs 6 secured together at their upper ends by cross pieces 'l and adjacent their lower ends by cross pieces 8. The supporting frame 5 is also provided with a horizontal top 9 formed centrally thereof with an opening I0 through which projects the upper end of the vertical sand and air distributing nozzle II. Welded or otherwise suitably secured to the side of the distributing nozzle II is a block I2 fastened by bolts or the like I3 to a bracket I4 carried upon the underside of the top 9.

Mounted within the lower end of thedistributing nozzle II is the air nozzle I5 having an opening I6 extending vertically theerthrough, said opening tapering towards its upper end and terminating in an outwardly flared lip Il. Fitted uponithe lower end of the distributing nozzle II is a .plate I8 having a peripheral flange I9 engaged by a nut 20 threaded upon the lower end of distributing nozzle IfI to securely hold the end plate I8 thereon. If desired, suitable packing material 2| may be arranged between the end plate and distributing nozzl Passing upwardly through the end plate I8 centrally thereof is a sand feed pipe 22 having threaded within its upper end the upwardly and outwardly flared sand nozzle 23. The upper end of the sand nozzle 23 is space-d from the inner wall of the air nozzle I5 to provide a continuous opening around the sand nozzle for the passage of air. The upper end of the sand nozzle 23 also terminates slightly beneath the flared lip Il of air nozzle I5.

Carried within the supporting frame 5 beneath the top 9 thereof is a hopper. 24 containing the f .supply of sand, emery or other abrasive 25 which 1s employed in the Imarking operation. Depending within the body of sand 25 is the lower end upper end with the feed pipe 22 by means of a T-coupli-ng 1|. Secured within the stem of the T-coupling 1| is a horizontal pipe 12 passing outwardly through the wall of hopper 24 and open at its outer end to the atmosphere. Carried at the outer end of pipe 12 is a stop cock 13 and by proper adjustment thereof, it is possible to obtain a closer control of the sand or other abrasive drawn upwardly through the supply conduit 26. The feed pipe 22 is adjustable vertically through the end plate I3 and may be secured in desired adjusted position by a setscrew 21.

' The end plate I8 is also provided with a pair of openings disposed at opposite sides of the sand feed pipe 22 and secured within 'these openings are the air inlet pipes 28 and 29 which converge upwardly and are connected at their lower ends, by connections 30 and 3|, to an air supply conduit 32 running to a suitable source of compressed air. Interposed within the air supply conrfduit 32 is a valve 33 carried upon the frame 5 by a bracket 34 and provided with a vertical stem 35 which is normally urged downwardly to maintain the valve closed. However, when the valve stem 35 is moved upwardly to open valve 33 compressed air will be delivered through supply conduit 32 and pipes 26 and 2-9 to the air nozzle l5 where it will form a supply of air ,in surrounding relation to the sand nozzle 23. As the compressed air passes upwardly beyond sand nozzle 23 it will draw the required amount of sand upwardly through the sand feed pipe 22 and sand nozzle 23. The sand and air will then mix with one another in the distributing nozzle and be forcibly ejected upwardly against the sheet or plate of laminated safety glass 36 which is supported horizontally above the outlet end of said distributing nozzle.

Carried upon the top '9 of supporting frame 5 and surrounding the upper end of distributing nozzle is a cylindrical metal shield 31 having at its lower end a flange 38 secured by suitable clamps or the like 39 to the top 9. Formed in the top of the shield 31 is an opening 40 and secured to the upper surface of said shield in surrounding relation to said opening is a pad 4|. 'I'he pad 4| is preferably of sponge rubber vulcanized to the bottom of a metal plate 14 which is removably secured to the shield by machine screws 15 so that the said pad may be readily replaced as required. For example, in Fig. 2 the stencil has cut therefrom the letters L-O-F and therebeneath the words Safety plate,` although obviously any other marking may be used. While the stencil may be of metal and in the form of a single plate, it is here shown as comprising a strip of plastic wound at its opposite ends upon the two rolls 43 and 44 carried in bearings 45 and 46 respectively. A plurality of stencils are preferably cut in the stencil strip 42, and in operation one of the stencils is located directly above the opening.

40 in shield 31. As the stencil becomes worn, the strip 42 can be wound upon either roll 43 or 44 to bring a fresh stencil into operative position. The sheet of safety glass 36 is supported at opposite sides of the shield 31 upon freely rotatable rollers 41 and 48, and to assist in locating the laminated sheet in proper position, there are provided the stop blocks 49 and 50 carried by brackets 5| and 52 and against which the rear edge of the sheet is butted when placed upon the rollers 41 and 46.

The apparatus also includes the provision of 2,328,350 of a sand supply conduit 26 connected at its` means for clamping the sheet of laminated glass 36 in place upon the shield 31 and for substantially simultaneously opening the valve 33 to effect thesand blast operation. Such means comprises a substantially horizontal clamping lever 53 pivoted intermediate, its ends as at 54 to the upper end of a bracket arm 55 carried by the top 9. The forward end of the lever 53 overlies the sheet of safety glass 36 and is provided with a presser foot 56 adapted to engage the same. Pivoted to the opposite end of the lever 53 as at 51 is a sleeve 58 ir which is threaded one end of a substantially vertical connecting rod 53, having threaded upon its opposite end a coupling 60; said coupling being slidably received within a cylindrical sleeve 6| pivoted as at 62 to the rear end of an operating lever or foot treadle 63. The sleeve 6| is provided with diametrically opposed vertical slots 64, while carried by the coupling 60 is a transverse pin having its opposite ends received in said slots 64. Arranged within the sleeve 6| is a compression spring 66 acting to normally urge the coupling 60 outwardly of said sleeve.

The foot treadle 63 is pivotally mounted intermediate its ends as at 61 upon a bracket 68 carried by the supporting frame 5 and is provided at its forward end with a foot 'engageable portion 69.

When it is desired to eect the sand blasting operation, it is simply necessary for the operator to first properly locate the sheet of safety glass 36 upon the supporting rollers 41 and 48 and to then press downwardly upon the forward end 69 of foot treadle 63. When this is done, the oonnecting rod 59 will be moved upwardly to swing the coupling lever 53 upon its pivot 54 and urge the forward end 56 thereof downwardly upon the glass to clamp it in place upon the top of shield 31. Upon continued downward movement of the forward end ofifoot treadle 63, the spring 66 will be slightly compressed so that the plate 10 carried by the'treadle will move upwardly to engage the valve stem 35 and open valve 33. Upon opening of the valve, compressed air will enter through the air supply conduit 32 and pass to the distributing nozzle il as described above. The air will draw sand upwardly through the sand nozzle 23 and cause it to be ejected from the distributing vnozzle through the cut out portions in the stencil 42 to effect the marking of the glass. As soon as the foot treadle 63 is released, the rear end thereof will move downwardly to release the safety glass and permit the valve to be automatically closed to shut olf the sand blast. With this arrangement, the foot treadle 63 is actuated to clamp the safety glass in place just slightly in advance of the opening of the valve 33, whereas after the sand blast operation the valve will close just slightly in advance of the release of the safety glass.

It is to be understood that the form of the in- Vention herewith shown and described is to be taken as the preferred embodiment of the same, and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoinedclaims.

I claim:

l. In sand blasting apparatus of the character described, means for supporting an` article to be marked, said supporting means having an opening therein, a stencil covering said opening, a cylindrical distributing nozzle behind said stencil in line therewith, a cylinderical air nozzle mounted in the outer end of said distributing nozzle and having its inner wall tapering inwardly, an abrasive nozzle having connection with an abrasive supply arranged within said air nozzle concentric therewith and flaring toward its discharge end, and means for introducing air under pressure into the outer end of said air nozzle in surrounding relation to said abrasive nozzle for drawing abrasive through said abrasive nozzle from said abrasive supply and ejecting it through the said sten` cil and against the article to be marked.

2. In sand blasting apparatus of the character described, means for supporting an article to be marked, said supporting means having an opening therein covered by a stencil, a nozzle behind ter described, means for supporting an article to be marked, said supporting means having an opening therein covered by a stencil, a nozzlebe-l hind said stencil in line therewith having connection with an abrasive supply, an air supply pipe for delivering air under pressure to said nozzle, a valve in said air supply pipe normally held closed, means for clamping the article to be marked upon said supporting means including a pivotally mounted lever, and means for actuating said lever to clamp the article in place and,

for substantially simultaneously opening said valve to permit air under pressure to enter said nozzle.

4. In sand blasting apparatus of the character described, means for supporting an article to be marked, said supporting means having an opening therein covered by a stencil, a nozzle behind said stencil in line therewith having connection with an abrasive supply, an air supply pipe for delivering air under pressure to said nozzle, a valve in said air supply pipe normally held closed, means for clamping the article to be marked upon said supporting means including a pivotally mounted clamping lever and a pivotally mounted operating lever, .a rod extending between and connecting said clamping lever and operating lever, said operating lever being under the control of the operator and adapted upon actuation thereof to cause said clamping lever to engage the article to be marked, and spring means associated with said operating lever for permitting additional movement thereof after said clamping lever engages said article to cause said operating lever to open said valve and permit air under pressure to enter said nozzle.

5. In sand blasting apparatus of the character described, means for supporting an article to be marked, said supporting means having an opening therein, a stencil covering said opening, a cylindrical distributing nozzle behind said stencil in line therewith and having an outlet opening, a cylindrical air nozzle mounted in the outer end of said distributing nozzle and having its inner wall tapering inwardly to an outlet opening relatively smaller than the outlet opening in said distributing nozzlean abrasive nozzle having connection with an abrasive supply arranged within said air nozzle concentric therewith and flared inwardly towards its discharge l end and spaced from the tapered inner wall of said air nozzle, and means for introducing air under pressure into the outer end of said air nozzle in surrounding relation tol said abrasive nozzle for drawing abrasive through said abrasive nozzle from said abrasive supply and electing it through said stencil and against the article to be marked. 6. In sand blasting apparatus of the character described, means for supporting an article to be marked, said supporting means having an opening therein, a stencil covering said opening, a cylindrical distributing nozzle behind said stencil in line therewith and having an outlet opening, a cylindrical air nozzle mounted in the outer' end of said distributing nozzle and having its inner wall tapering inwardly to an outlet opening relatively smaller than the outlet opening in said distributing nozzle and terminating in an outwardly ilared lip, an abrasive nozzle having connection with an abrasive supply arranged within said air nozzle concentric therewith 'and ared inwardly towards its discharge end and spaced from the tapered inner wall of said air nozzle, and means for introducing air under pressure into the outer end of said air nozzle in surrounding relation to said abrasive nozzle for drawing abrasive through said abrasive nozzle from said abrasive supply and ejecting it through said stencil and against the article to be marked.

ELMER H. LINDENMEYER. 

